Strand handling apparatus



Aug 5, 1941. L. o. REICHELT s'rmmn HANDLING APPARATUS Filed Aug. 10,1940 2 Sheets-Sheet 1 4 nv VENIUR L 0.REICHEL 7' RAwfi A rromverPatented Aug 5, 1941 OFFICE STRAND HANDLING APPARATUS Lester 0.Reichelt, Cranford, N. L, minor to Western Electric Company,Incorporated, New York, N. Y., a corporation of New' York ApplicationAugust 10, 1940, Serial No. 352,054

10 Claims. (Cl. 254-135) This invention relates to strand handlingapparatus, and more particularly to apparatus for advancing strandslongitudinally of themselves.

In the arts which pertain to the manufacture of strands, especially ofthe many kinds of compound strands, cords, ropes, cables, etc., employedfor both mechanical and electrical purposes, there is need for apparatusto pull the strands from or through the various devices and machinesused to make or variously treat them. Generally speaking such devicesfall into two principal classes, rotary capstans and tractor capstans,each with its peculiar and inherent defects and advantages. A principaladvantage of the rotary capstan, which is essentially a driven drumaround which the strand to be advanced is wrapped in a sufficient numberof turns to effect the required frictional grip, is that a given capstanmay be used without alteration or adjustment of any kind for strandshaving a large range of diameters. A principal inherent defect of therotary capstan is that a strand of relatively large each other on eachside of a'straight segment of the strand to be moved, and which areprovided with suitable tractor blocks or other means on the belts togrip, carry along and release the strands, and with means such assuitable cam tracks to press the blocks into gripping engagement withthe strand passing between them. Such tractor capstans have the inherentadvantage of operating on a straight portion of strand. There is nobending of the strand under tension,

and hence no diiferential tension imposed within the strand because ofbending. On the other hand, such tractor capstans have the inherentdisadvantage of being capable of handling strands of practically onlyone diameter without a difficult and tedious removal and interchange ofbelts.

An object of the present invention is to provide a strand advancingapparatus generally of the tractor capstan type provided with simple,

durable, inexpensive and reliable means whereby the apparatus may beemployed to advance strands having a relatively large range of diameterwithout interchange of parts. I

With the above and other objects in view, the invention may be embodiedin a tractor capstan in which the strand gripping elements are providedwith strand gripping surfaces generally cylindrical in cross-section andhaving portions of two separate degrees of curvature, which elements mayfurther be composed. of resilient main accordance with the invention;

Fig. 2 is an enlarged section on the line 22 of Fig. l; i

Fig. 3 is a partial view similar to Fig. 2, showing application to astrand of minimum diameter;

Fig. 4 is a section on the line 4-4 of Fig. 2;

Fig. 5 is a view similar to Fig. 3, showing a strand of intermediatediameter; and

Fig. 6 is a partial view of a modified form of gripping member.

In the embodiment herein disclosed, a tractor capstan generally shown inFig. 1 is provided with two tractor belts 20 and 2| of any suitablematerial and construction, here indicated as sprocket chains. Theportions of the two belts which face each other are always parallel toeach other. The belts are drivable so that the mutually facing parallelportions run at the same speed and in the same direction. The generalstructure and mode of operationof the capstan are no part of the presentinvention and so are not disclosed or described here. A suitablestructure is disclosed and described in U. S. Patent No. 1,882,902 ofOctober 18, 1932, to the present inventor, to which referencemay be had,if desired, for such information.

For present purposes all that is necessary as to r the machine generallyis that the mutually facing portions of the belts 20 and 2i are drivableto :run in strict parallelism, from left to right in Fig. 1; at the samespeed; that means be provided as in the patent above cited for adjustingthe distance apart of the belts; and that means are present such as ahollow shaft It to lead a strand l9 to be advanced, propelled or drawnalong from left to right, to enter between the belts.

As herein disclosed, each of the belts 20 and 2| consists of threedistinct parallel sprocket chains, bound together at each link bytransverse crossbars 22 and 23, respectively, of metal, each secured tothree laterally aligned links of the three chains by being secured withrivets 25 to supporting arms 24 formed integral with the links. Each ofthe crossbars 22 and 23 is formed with a dovetail slot 26 runninglongitudinally of the bar and transversely to the belts and located inthe face oi the bar away from its supporting belt.

A mounting member 21 or 28 respectively, of metal. has a base portioncorresponding in width to the slotted face of the cross bar and isformed on the under side oi. its base with a dovetail to match thedovetail slot 26 and assembled therein. The base dovetail is locked intoexact position in the slot 26 by a. permanent stop 29 at one end and aspring lock 30 at the other. Thus each of the mounting members 21 or 28may be removed individually at will for exchange or repair.

The upstanding body oi each mounting member 21 is relatively wide, asherein shown spanning all three chains of the belt 2i. The dependingbody of each member 28 is relatively narrow, spanning, in the structuredisclosed, substantially only the middle chain of the belt 20. The topsurface of the member 21 and the bottom surface of the member 28 areeach curved to a radius somewhat greater than that of the largest strandto be handled by the particular assembly, and each of these faces isformed with a correspondingly arcuate dovetail slot 3| or 32respectively.

A gripping member 33 or 34, preferably of rubber or the like material,is formed, pressed and Vulcanized into each slot 3| or 32 respectivelyto be securely gripped therein. Each of the members 33 has in its upperface a semi-cylindrical slot or groove 35 whose radius is that of thelargest strand to be handled, except at the bottom. Here there is afurther groove 36 cut into the bottom of the groove 35 with a radiusequal to that of the smallest strand in view, and preferably with awidth of about 90, the sharp intersection of the two curved surfacesbeing smoothly faired away. The bottom face of each gripping member 34is curved to the radius of the largest strand in view, as at 31. In thepreferred form, as noted above, the members 33 or 34 are of somerelatively softly resilient material such as rubber. They may then bemolded in place as described to be substantially homogeneous. Or theymay, in some instances preferably, be partiallypreformed of laminationsof fabric impregnated with uncured rubber material and cured after beingput in place in the members 21 or 28. Or in other instances the members21 and 33 or 28 and 34 or both may be made integral and of metal, whilepreserving the particular contours of the gripping surfaces 35 and 36 or31 as described.

The operation of the members 33 and 34 in gripping a strand to beadvanced is thought to be self-evident from the above description of theapparatus. It may be noted that in any given case the distance apart ofthe belts 20 and 2| will be adjusted to an optimum value which will berelated to the diameter of the particular strand in question in a mannerdependent upon the structure and nature of the particular strand, theseverity of the grip upon the strand in turn depending upon thedifference between the ungripped diameter of the strand and the emptydistance between the opposed faces of the gripping members. Generally,both the members 33 and 34 on the one hand and the strand gripped bythem on the other, will be more or less deformed by the grippingpressure. At one extreme is the case where the members 33 and 34 are ofrelatively soft rubber and the strand a solid rod of metal or a closelylaid cable of hard metal strands, in which case there is no deformationof the strand. At bers 33 and 34 of relatively soft and such case, therewill gripping members.

deformable the other extreme the memmay be of metal and the strandmaterial. In

be no deformation of the In the particular case of the handling ofcompound strands such as telephone cable cores,

composed of a plurality of wires intertwisted together as a whole or inpre-twisted groups, the

invention has its principal practical value.

cores, in practise, at various stage Such s of manufacture, may besimply such compound strands of intertwisted wire, or they may have abinder strand wound about pitch, or they may, as illustrated the strandill, have a wrapping completely covering them. Such them at relativelyshort in the case of of paper tape cores will endure a certain amount ofdeformation under transverse squeezing obviously not a great deal.

without material injury but When a maximum diameter core, such as i9,

is gripped as in Figs. 2 and 4, the

gripping pressure is applied over something like two thirds of thecircumference of the core, the resilient surfaces 35 and relativelysoft,

31 accommodate themselves not only to the general contour of the corebut also to the minor irregularities, and a relatively heavy tractiveeffort may applied to the core.

In the case of a minimum diameter core illustrated in Fig. 3, thesurface 36 makes contact with the core over a quarter of the beharmlessly I l, as close circumference without any deformation ofeither; and only a slight and negligible deformation at the uppercontact of the core is n the surface 31 and the core con over anotherquarter of the circumference. cases where extreme tenderness of actionis quired, the upper member with a secondary in the member 33, erally,however, this is The most common trated in Fig. 5, where the core Igroove I36 like ceded to make form together In 34 may even be formed thegroove 36 as illustrated in Fig. 6. Gennot found to be necessary.intermediate case is illus- 6 has a diameter intermediate between theleast and greatest. The figure illustrates, as do the others also, animpossible state in which there is no deformation of any of the elementsinvolved. there will be both a flattening of In actuality the core l6 atthe top and a deepening of the surface 31 under the gripping pressure.But a in will show that only a practically formation of the strand isrequir the concomitant deformation of t to spread the tangency grippingmembers from the idea oments study negligible deed, in view of hesurface 37,

of the core and upper 1 line contact illustrated over a veryconsiderable angular portion of the circumference of the c ore. The caseat the bottom is similar. Ideally the core makes contact with the member33 only along two lines where the surface 36 35. In actuality only isfaired off into the surface negligible mutual deformations are requiredto flatten down the faired ridges and correspondingly shallowly indentthe core so that contact between the gripping member and the core isestablished over the whole surface 36, the faired ridges andconsiderable angular fractions of the surface 35 on both sides.

Thus by the employment of gripping members preferably of resilientmaterial, which are mutually approximable for coaction, and

whose strand gripping surfaces are primarily curved to fit the largeststrand in view and of which may have a portion secondarily cu either orboth rved to fit the smallest strand contemplated, it is possiblesatisfactorily to grip and exert tractive effort on a strand of any of alarge range of diameters without material injury to either the strand orthe apparatus and without need for interchangeable gripping members.

The embodiment of the invention disclosed is illustrative and may bevariously modified and departed from without departing from the spiritand scope of the invention as pointed out in and limited only by theappended claims.

What is claimed is:

1. In apparatus of the general character described, a pair of opposedand mutually approximable gripping members for gripping therebetween astrand of any diameter between and including predetermined maximum andminimum values, each such gripping member having a strand grippingsurface .primarily cylindrically curved to fit a strand of maximumdiameter.

2. In apparatus of the general character described, a pair of opposedand mutually approximablegripping members for gripping therebetween astrand of any diameter between and including predetermined maximum andminimum values, each such gripping member having a strand grippingsurface primarily cylindrically curved to fit a strand ,of maximumdiameter, and each such gripping member being composed of elasticallyresilient material.

3. In apparatus of the general character described, a pair of opposedand mutually approximable gripping members for gripping therebetween astrand of any diameter between and including predetermined maximum andminimum values, each such gripping member having a strand grippingsurface primarily cylindrically curved to fit a strand of maximumdiameter, one of the gripping members also having its said strandgripping surface further formed over a portion thereof with acylindrical curvature to fit a strand of minimum diameter.

4. In apparatus of the general character described, a pair of opposedand mutually approximable gripping members for gripping therebetween astrand of any diameter between and including predetermined maximum andminimum values, each such gripping member having a strand grippingsurface primarily cylindrically curved to fit a strand of maximumdiameter, one of the gripping members also having its said strandgripping surface further formed over a portion thereof with acylindrical curvature to fit a strand of minimum diameter and having thejunctures of the two portions of difierent curvature faired away.

5. In apparatus of the general character described, a pair of opposedand mutually approximable gripping members for gripping therebetween astrand of any diameter between and including predetermined maximum andminimum values, each such gripping member having a strand grippingsurface primarily cylindrically curved to fit a strand of maximumdiameter, each of the gripping members also having its said strandgripping surface further formed over a portion thereof with acylindrical curvature to fit a strand of minimum diameter.

6. In apparatus of the general character described, a pair of opposedand mutually approximable gripping members for grippin therebetween astrand of any diameter between and including predetermined maximum andminimum values, each such gripping member having a strand grippingsurface primarily cylindrically curved to fit a strand of maximumdiameter, each of the gripping members also having its said strandgripping surface further formed over a portion thereof with acylindrical curvature to fit a strand of minimum diameter and having thejunctures of the two portions of different curvature faired away.

7. In apparatus of the general character described, a pair of opposedand mutually approximable gripping members for gripping therebetween astrand of any diameter between and including predetermined maximum andminimum values, each such gripping member having a strand grippingsurface primarily cylindrically curved to fit a strand of maximumdiameter, one of the gripping members also having its said strandgripping surface further formed over a portion thereof with acylindrical curvature to fit a strand ofminimum diameter and each suchgripping member being composed of elastically resilient material.

8. In apparatus of the general character described, a pair of opposedand mutually approximable gripping members for gripping therebetween astrand of any diameter between and including predetermined maximum andminimum values, each such gripping member having a strand grippingsurface primarily cylindrically curved to fit a strand of maximumdiameter, one of the gripping members also having its said strandgripping surface further formed over a portion thereof'with acylindrical curvature to fit a strand of minimum diameter and having thejunctures of the two portions of different curvature faired away andeach such gripping member being composed of elastically resilientmaterial.

9. In apparatus of the general character tie-'- scribed, a pair ofopposed and mutually approximable gripping members for grippingtherebetween a strand of any diameter between and includingpredetermined maximum and minimum values, each such gripping memberhaving a strand gripping surface primarily cylindrically curved to fit astrand of maximum diameter, each of the gripping members also having itssaid strand gripping surface further formed over a portion thereof witha cylindrical curvature to fit a strand of minimum diameter and eachsuch gripping member being composed of elastically resilient material.

10. In apparatus of the general character de scribed, a pair of opposedand mutually approximable gripping members for gripping therebetween astrand of any diameter between and including predetermined maximum andminimum values, each such gripping member having a strand grippingsurface primarily cylindrically curved to fit a strand of maximumdiameter, each of the gripping members also having its said strandgripping surface further formed over a portion thereof with acylindrical curvature to fit a strand of minimum diameter and having thejunctures of the two portions of different curvature faired away andeach such grippin member being composed of elastically resilientmaterial.

LESTER o. REICHELT. I

